No, there's no way to know if CIC has received it until they charge your credit card or they return your application.
There's a small trick you can try but it works depending on your luck. Go to the same Canada Post and cry a little bit. The person who will attend you will have to do some research in their system, but they have access to that information and they can give you the tracking number. In the case of Canada Post you'll have to be very precise and tell them exactly which day and at what time you sent it because they don't store the name of the person who sends the letter.